Microwave Oven Microwave Oven Greetings, The Southwest Museum of Engineering, Communication and Computation is seeking : artifacts, books, papers, personal recollections, funny stories, newspaper clipping, magazines, catalogs, articles torn out of magazines, cartoons, prototype magnetrons, really early microwave ovens etc ANYTHING Is Fair Game! The purpose is two-fold which consists of construction the display in the museum in Glendale Arizona and also as an addition to our web site. thanks Ed Sharpe archivist for SMECC Please check our web site at to see other engineering fields, communications and computation stuff we buy, and by all means when in Arizona drop in and see us. address: thanks Ed Sharpe archivist for SMECC The microwave oven was invented as an accidental by-product of war-time (World War 2) radar research using magnetrons (vacuum tubes that produce microwave radiation, a type of electromagnetic radiation that has a wavelength between 1 mm and 30 cm). In 1946, the engineer Dr. Percy LeBaron Spencer, who worked for the Raytheon Corporation, was working on magnetrons. One day at work, he had a candy bar in his pocket, and found that it had melted.

He realized that the microwaves he was working with had caused it to melt. After experimenting, he realized that microwaves would cook foods quickly - even faster than conventional ovens that cook with heat. The Raytheon Corporation produced the first commercial microwave oven in 1954; it was called the 1161 Radarange. It was large, expensive, and had a power of 1600 watts. The first domestic microwave oven was produced in 1967 by Amana (a division of Raytheon). In 1967, Amana, a division of Raytheon, introduced its domestic Radarange microwave oven, marking the beginning of the use of microwave ovens in home kitchens. Although sales were slow during the first few years, partially due to the ovenï¿½s relatively expensive price tag, the concept of quick microwave cooking had arrived. In succeeding years, Litton and a number of other companies joined the countertop microwave oven market. By the end of 1971, the price of countertop units began to decrease and their capabilities were expanded. Spencer, born in Howland, Maine, was orphaned at a young age.

Although he never graduated from grammar school, he became Senior Vice President and a member of the Board of Directors at Raytheon, receiving 150 patents during his career. Because of his accomplishments, Spencer was awarded the Distinguished Service Medal by the U.S. Navy and has a building named after him at Raytheon. Percy Spencer, while working for the Raytheon Company, discovered a more efficient way to manufacture magnetrons. In 1941, magnetrons were being produced at a rate of 17 per day. Spencer set out to create a simpler magnetron that could be mass produced. The result was a magnetron that replaced precision copper bars with lamina and replaced soldered internal wires with a simple solid ring. These improvements and others allowed for the faster production of 2,600 magnetrons per day. In 1945, Spencer created a device to cook food using microwave radiation. Raytheon saw the possibilities of this, and after acquiring Amana Refrigeration in 1965, was able to sell microwave ovens on a large scale. The first microwave oven was called the Radarange, and today, there are over 200 million in use throughout the world.

A Brief History of the Microwave Oven By J. Carlton Gallawa , author of THE COMPLETE MICROWAVE OVEN SERVICE HANDBOOK Like many of today's great inventions, the microwave oven was a by-product of another technology. It was during a radar-related research project around 1946 that Dr. Percy Spencer, a self-taught engineer with the Raytheon Corporation, noticed something very unusual. He was testing a new vacuum tube called a magnetron (we are searching for a picture of an actual 1946 magnetron), when he discovered that the candy bar in his pocket had melted. This intrigued Dr. Spencer, so he tried another experiment. This time he placed some popcorn kernels near the tube and, perhaps standing a little farther away, he watched with an inventive sparkle in his eye as the popcorn sputtered, cracked and popped all over his lab. The next morning, Scientist Spencer decided to put the magnetron tube near an egg. Spencer was joined by a curious colleague, and they both watched as the egg began to tremor and quake. The rapid temperature rise within the egg was causing tremendous internal pressure.

Evidently the curious colleague moved in for a closer look just as the egg exploded and splattered hot yoke all over his amazed face. The face of Spencer lit up with a logical scientific conclusion: the melted candy bar, the popcorn, and now the exploding egg, were all attributable to exposure to low-density microwave energy. Thus, if an egg can be cooked that quickly, why not other foods? Experimentation began... Dr. Spencer fashioned a metal box with an opening into which he fed microwave power. The energy entering the box was unable to escape, thereby creating a higher density electromagnetic field. When food was placed in the box and microwave energy fed in, the temperature of the food rose very rapidly. Dr. Spencer had invented what was to revolutionize cooking, and form the basis of a multimillion dollar industry, the microwave oven. (Click HERE to learn even more about Dr. Percy Spencer) Nearly 6 Feet Tall, Weighing 750 Pounds Engineers went to work on Spencer's hot new idea, developing and refining it for practical use. By late 1946, the Raytheon Company had filed a patent proposing that microwaves be used to cook food.

An oven that heated food using microwave energy was then placed in a Boston restaurant for testing. At last, in 1947, the first commercial microwave oven hit the market. T hese primitive units where gigantic and enormously expensive, standing 5 1/2 feet tall, weighing over 750 pounds, and costing about $5000 each. The magnetron tube had to be water-cooled, so plumbing installations were also required. Initial Reactions Were Unfavorable Not surprisingly, many were highly reluctant about these first units, and so they found only limited acceptance. Initial sales were disappointing...but not for long. Further improvements and refinements soon produced a more reliable and lightweight oven that was not only less expensive, but, with the development of a new air-cooled magnetron, there was no longer any need for a plumber. The microwave oven had reached a new level of acceptance, particularly with regard to certain industrial applications. By having a microwave oven available, restaurants and vending companies could now keep products refrigerator-fresh up to the point of service, then heat to order. The result? Fresher food, less waste, and money saved.

New and Unusual Applications As the food industry began to recognize the potential and versatility of the microwave oven, its usefulness was put to new tests. Industries began using microwaves to dry potato chips and roast coffee beans and peanuts. Meats could be defrosted, precooked and tempered. Even the shucking of oysters was made easier by microwaves. Other industries found the diverse applications of microwave heating quite advantageous. In time, microwaves were being used to dry cork, ceramics, paper, leather, tobacco, textiles, pencils, flowers, wet books and match heads. The microwave oven had become a necessity in the commercial market and the possibilities seemed endless. The First "Radarange" In 1947, Raytheon demonstrated the world's first microwave oven and called it a "Radarange," the winning name in an employee contest. Housed in refrigerator-sized cabinets, the first microwave ovens cost between $2,000 and $3,000. Sometime between 1952-55, Tappan introduced the first home model priced at $1295. In 1965 Raytheon acquired Amana Refrigeration.

Two years later, the first countertop, domestic oven was introduced. It was a 100-volt microwave oven, which cost just under $500 and was smaller, safer and more reliable than previous models. By 1975 Sales of Microwave Ovens Exceeded that of Gas Ranges Technological advances and further developments led to a microwave oven that was polished and priced for the consumer kitchen. However, there were many myths and fears surrounding these mysterious new electronic "radar ranges." By the seventies, more and more people were finding the benefits of microwave cooking to outweigh the possible risks, and none of them were dying of radiation poisoning, going blind, sterile, or becoming impotent (at least not from using microwave ovens). As fears faded, a swelling wave of acceptance began filtering into the kitchens of America and other countries. Myths were melting away, and doubt was turning into demand. By 1975, sales of microwave ovens would, for the first time, exceed that of gas ranges. The following year, a reported 17% of all homes in Japan were doing their cooking by microwaves, compared with 4% of the homes in the United States the same year.

Before long, though, microwave ovens were adorning the kitchens in over nine million homes, or about 14%, of all the homes in the United States. In 1976, the microwave oven became a more commonly owned kitchen appliance than the dishwasher, reaching nearly 60%, or about 52 million U.S. households. America's cooking habits were being drastically changed by the time and energy-saving convenience of the microwave oven. Once considered a luxury, the microwave oven had developed into a practical necessity for a fast-paced world. An expanding market has produced a style to suit every taste; a size, shape, and color to fit any kitchen, and a price to please almost every pocketbook. Options and features, such as the addition of convection heat, probe and sensor cooking, meet the needs of virtually every cooking, heating or drying application. Today, the magic of microwave cooking has radiated around the globe, becoming an international phenomenon. Inventor Spencer Doctor Spencer continued at Raytheon as a senior consultant until he died at the age of 76. At the time of his death, Dr.

Spencer held 150 patents and was considered one of the world's leading experts in the field of microwave energy, despite his lack of a high school education. On September 18, 1999, Dr. Percy LaBaron Spencer was inducted into the National Inventors Hall of Fame and took his place in history alongside such great inventors as Thomas Edison, the Wright Brothers and George Washington Carver. More to come on the fascinating history and development of the microwave oven... Note: Photo of Percy Spencer and Patent provided courtesy of The Spencer Family Archives Picture of the earliest microwave oven provided courtesy of The Lemelson-MIT Awards Program's Invention Dimension web site, Picture of Original Microwave Oven Patent by Doctor Percy L. Spencer Courtesy Rod Spencer and the Spencer Family Archives Copyright Information Unless otherwise noted, all materials at this cite (including without limitation all text, html markup, graphics, and graphic elements) are copyrighted ï¿½, 1989-2001 by J. Carlton Gallawa. The material available through this site may be freely used for attributed noncommercial educational purposes only. We ask that due credit and notification be given the author.

Amana Radarange Amana Refrigeration, a subsidiary of Raytheon Manufacturing Company, in 1967 introduced this first compact microwave oven, called the Radarange. It was a 115 V countertop model, retailing for $495, and cooked hamburgers in 35 seconds. The compact size was made possible by a small, efficient electron tube, developed in 1964 by the Japanese, which replaced older, bulkier tubes called magnetrons. In 1968, tests by Walter Reed Hospital confirmed many fears that microwaves did, in fact, leak out of the ovens, but Federal standards set in 1971 resolved the problem. By 1994, ninety per cent of all US homes had such an appliance. The first microwave ovens for home consumer use were introduced by Tappan in 1955, but few purchased them due to their large size (about like an electric stove) and high cost. Microwave ovens were a spin-off of wartime RADAR, and invented accidentally by Percy LeBaron Spencer of Raytheon while working on a magnetron (radar tube) near the end of the war.

As he passed the device, which generated microwaves, he noticed that a candy bar in his pocket began to melt. He experimented with eggs (they exploded) and popcorn (it popped). So, a "high frequency dielectric heating apparatus" was patented in 1945 by Raytheon, and a prototype built. The first microwave oven for commercial purposes (ships and hotels) was introduced in 1947 by Raytheon, and named the Radar Range. It stood five and a half feet tall, weighed 750 pounds, and cost $3000 30th Anniversary of Microwave Oven Marks Revolution in Americaï¿½s Home Kitchens Microwave Oven History - Invention of the Microwave Oven . MICROWAVE OVEN The microwave oven did not come about as a result of someone trying to find a better, faster way to cook. During World War II, two scientists invented the magnetron, a tube that produces microwaves. Installing magnetrons in Britains radar system, the microwaves were able to spot Nazi warplanes on their way to bomb the British Isles. By accident, several years later, it was discovered that microwaves also cook food.

Called the Radar Range, the first microwave oven to go on the market was roughly as large and heavy as a refrigerator. The idea of using microwave energy to cook food was accidentally discovered by Percy LeBaron Spencer of the Raytheon Company when he found that radar waves had melted a candy bar in his pocket. Experiments showed that microwave heating could raise the internal temperature of many foods far more rapidly than a conventional oven. The first Raytheon commercial microwave oven was the 1161 Radarange, which was marketed in 1954. Rated at 1600 watts, it was so large and expensive that it was practical only for restaurant and institutional use. In 1967, Amana, a division of Raytheon, introduced its domestic Radarange microwave oven, marking the beginning of the use of microwave ovens in home kitchens. Although sales were slow during the first few years, partially due to the ovens relatively expensive price tag, the concept of quick microwave cooking had arrived. In succeeding years, Litton and a number of other companies joined the countertop microwave oven market. By the end of 1971, the price of countertop units began to decrease and their capabilities were expanded.

All electromagnetic energy can be characterized as waves with a specific wavelength and frequency distributed over a continuous range known as the electromagnetic spectrum. For example, some radio waves have a wavelength of 6 feet (12 meters) and a frequency of 50 million hertz (Hz-cycles per second). Visible light waves have a wavelength of 400 to 700 millimicrons, and typical X-rays have a length of 0.01 millimicrons and a frequency of 30 x 10ï¿½ï¿½ millions. Microwaves (short waves or high frequency radio waves) are the shortest of radio waves, with a length of 0.1 millimeter and a frequency of 3 x 109 Hz. They are found in the non-ionizing portion of the energy spectrum, between radio waves and visible light. "Non-ionizing" means that microwaves do not detach charged particles and produce atoms with an unbalanced plus or minus charge. Microwaves can therefore safely produce heat and not cause food to become radioactive. Microwaves are reflected from most metals but they produce inductive resonance's in the atoms of many other substances.

It was the discovery of their reaction to metals that led to the invention of radar. It was their ability to produce resonant coupling that led to the invention of the microwave oven. TO LEARN MORE 8. Microwave Ovens - 9 Things Invented or Discovered by Accident | HowStuffWorks 9 Things Invented or Discovered by Accident Microwave Ovens The microwave is the result of an observation during a science experiment. The microwave oven is now a standard appliance in most American households, but it has only been around since the late 1940s. In 1945, Percy Spencer was experimenting with a new vacuum tube called a magnetron while doing research for the Raytheon Corporation. He was intrigued when the candy bar in his pocket began to melt, so he tried another experiment with popcorn . When it began to pop, Spencer immediately saw the potential in this revolutionary process. In 1947, Raytheon built the first microwave oven, the Radarange, which weighed 750 pounds, was 51/2 feet tall, and cost about $5,000.

When the Radarange first became available for home use in the early 1950s, its bulky size and expensive price tag made it unpopular with consumers. But in 1967, a much more popular 100-volt, countertop version was introduced at a price of $495. Microwaves101 | History of the Microwave Oven internet of things ios attenuator calculator History of the Microwave Oven Click here to go to our main page on microwave history Click here to go to our page on heating with microwaves Scan of original Radarange logo, courtesy of Wendy Bock Mitchell New for March 2013! Learn about David Arthur Copson The microwave oven was developed after W.W.II in order to beat swords into plowshares. Perhaps the engineer who is best known for birthing the idea of using microwaves to prepare food was Percy Spencer, of the Raytheon Company, located in Waltham Massachusetts. Many non-engineers have the perception that a lone inventor goes into a lab for a few months or years, and creates an invention like the automobile or the cell phone by himself. That is almost never the case.

Multiple contributors, performing hard work as a team or as individuals, slowly evolve an idea into a product that every once in a while changes the world. Like most other breakthroughs, the microwave oven was a group effort and did not happen overnight. One of the subject matter experts on this topic is John Osepchuk, who worked at Raytheon during the 60s, 70s and 80s. His papers on the topic include: "A History of Microwave Heating Applications", IEEE Transactions on Microwave Theory and Techniques, Vol. MTT-32, No. 9. Sept. 1984, pp 1205- "The History of the Microwave Oven: A Critical Review", IMS 2009, pp 1397-1400 (it's easy to find this article on the internet...) John has complained in recent years at IEEE talks that some web sites propose that the microwave oven was invented in Russia, or Germany, but then again, you can find almost any incorrect "fact" you you are looking for on the internet.

Below is a video of John talking about the invention of the microwave oven: John Osepchuk explains some microwave oven history Also, we refer to The Creative Ordeal, The Story of Raytheon, by Otto J. Scott, published in 1974. This book commemorates the 50th anniversary of the Raytheon Company. Readers should be aware that such autobiographical efforts contain a wealth of information but have been put through a corporate filter, and can often distort the truth either by omission of details, politics, or simple corporate favoritism. This web page will draw on Osupchuk's and Scott's publications, as well as the US patent office , and remarkably, the accounts of of an eye witness, a girl who consumed far too many hot dogs as her father tinkered on early oven prototypes in the family garage... Percy Spencer Percy Spencer 9 July, 1894 â€“ 8 September, 1970 Much work was afoot in the latter days of W.W.II by Daddy Warbucks companies looking for industrial heating applications of microwaves, including diathermy, and industrial heating of products such as inks, glue, and tires.

Anyone who worked around the magnetron burn-in stand knew that "soft" objects such as people would start to heat up if they were to stay in the direct path of high-power microwave radiation. Maybe John will send us a picture of the burn-in stand one of these days... Spencer's thoughts turned to heating food; legend has it that a candy bar melted in his pocket from stray radiation. However, he could not have been thinking of a consumer application, as the high cost of microwave equipment would prevent widespread home use. Raytheon was not alone in looking at heating applications, General Electric reported on equipment that would thaw and heat frozen meals in a restaurant, using ~1 GHz energy (see Osepchuk). Spencer's original US patent 2,495,429 , Method of Treating Foodstuffs, was filed October 8, 1945 and granted on January 24, 1950. In this patent he points out the choice of frequency which provides high heating efficiency, the size of the cavity, and some superfluous details on the magnetron oscillator itself.

He envisioned a conveyor belt for parading the food into the cavity, no mention of safety, or how the radiation might be enclosed or how the food might enter the cavity (like a door). In a second patent 2,480,679 Spencer shows the now-ubiquitous use of microwaves to pop popcorn. In a later patent 2,540,036 , filed March 26, 1948, and granted January 30, 1951, entitled "Food Cooking", Spencer discusses how you might "broil" a lobster in a microwave oven, by violating said lobster with a "pencil like rod", in order so that its tail doesn't curl up which would make harder to cook. Yikes! The FCC was petitioned by Raytheon and General Electric, who each wanted to propose a frequency for their own work. Thus two frequencies were allocated, 915 +/-25 MHz and 2450 +/-50 MHz. To this day these are the Industrial/Scientific/Medical bands , and billions of cell phones and other wireless devices all communicate within them in the United States and elsewhere.

And, of course, billions of meals are prepared each day using 2.45 GHz electromagnetic radiation. Other Raytheon employees who worked on the microwave oven The Creative Ordeal credits Lawrence Marshall and Fritz Gross with some of the early work on the "Radarange". Radarange was chosen for the product in an employee competition, combining the words radar and range. (Why they didn't add a "y" to create "Raydarange" to acknowledge the Raytheon company is a mystery to me... - UE). Marshall was president of the company, so it is safe to say his main contribution was leadership; knowing that this was a project worthy of financial support during tough times. Fritz Gross was chief engineer of the Equipment Division. However, the two often met after hours in the laboratory to experiment with oven concepts. At one point they coupled a magnetron to a galvanized trash can, and used the apparatus to heat water. Later they had a cabinet built, and performed cooking experiments with gingerbread mix (just beginning to appear in stores), the smell was everywhere. The Creative Ordeal also mentions Sam Hathaway (helped refine the design), John Dawson (supervisor of oven and control circuit development) and G.E.M.

Bartram (production). Dawson did receive one microwave-related patent, 2,609,497 , for a modification of the magnetron itself, really nothing to do with cooking. No other US patents were issed to the others mentioned in this timeframe. Marvin Julian Bock Using 2.45 GHz to heat popcorn and lobsters must be first credited to Percy Spencer. However, the engineer that reduced the idea to practice, and developed the first practical, commercially viable microwave oven known as the Radarange, was Marvin Bock. Some details of his life: Born: December 31, 1914, New York Marvin graduated from Pratt. Death: March 27, 1971, Santa Barbara, California. Electronic Engineer, 29 years with Raytheon These words are from Marvin's daughter, Wendy. My dear father, Marvin J. Bock (1914-1971) was an electrical engineer in Percy Spencer's R&D laboratory at Raytheon, and did indeed participate in the development of the microwave oven during the 1940s. Marvin was a quiet man with a profound sense of integrity.

He was an engineer not a manager and was never concerned about his name being on the door. He wanted to be in his laboratory and design systems. I heard that he was very proud of the work he did developing radar equipment for battleships. Until recently I did not understand why he did not pursue his own recognition but I have come to believe that his development of the microwave oven was just not the important invention for him. He went to the World's Fair in Montreal to "present the oven to the world" and died 4 years later, not really having a sense of the importance of the oven. We had the original microwave in our garage in Needham when I was born in 1945 and I have the silver "Radarange" name plate from that oven. From what I read in articles, in 1947 Marvin was appointed head of the microwave heating laboratory at Waltham. In 1949 he was named assistant head of the radio frequency and antenna department of Raytheon's Missile Systems Laboratory at Waltham and this is where his focus turned to the Sparrow and Hawk missiles. We moved to the San Fernando Valley in 1953 and my father worked in Oxnard at Point Mugu.

We moved to Santa Barbara in 1956. This quote is from Osepchuk's 1984 article, which confirms Bock's contribution: "Enthused Raytheon management sponsored a contest for a name for the microwave oven and the Radarange (TM) was born. Marvin Bock, who later worked with Tom Philips, today's CEO, built the first Radarange, the Model 1132, which provided an output power of 1.6 kW from one water-cooled, permanent-magnet magnetron. This is shown in Fig. 3. Note that it was a free standing white-enameled unit operating from 220 V." Mr. Bock held five US patents, including one related to microwave heating: 2,516,503 filed December 14, 1946 and issued in July 25, 1950 and titled "Controlling Device for Cooking Apparatus". It discloses a means for shutting off microwave power when a food load is not present in a microwave cooking system, an important feature that the average user wouldn't even know about.

To learn more about engineer Marvin Bock, here's an article from the Santa Barbara News Press, November 16, 1958 "Men of Science" series. Marvin Julian Bock Thus from four accounts, Osupchuk, the USPTO, The Santa Barbara News Press, and Marvin's daughter, we know that Marvin Bock did indeed contribute heavily to the development of the Radarange, the world's first commercially successful microwave oven. The Creative Ordeal fails to mention his name even once; as we implied before, corporate history accounts are never 100% complete and accurate. It should be noted that the microwave oven didn't become a household appliance until 1967, when Raytheon began to market a countertop version of the Radarange though its subsidiary, Amana. You can learn more about the Radarange history at Raytheon's web site history page . David Arthur Copson This came from Tilan (thanks!) I came across your website and note you are missing information on a contributor to the development of microwave heating. His name is David Arthur Copson, born in Dorchester, MA in 1918.

He worked at Raytheon with many of the other folks you listed, and wrote three books, two on Microwave Heating. He was head of the Microwave Heating laboratory in Raytheon (not sure which years, but I'm researching it) and developed the proper methods for heating foods using microwave technology. He holds several patents in the field. Copson was awarded four US patents for his work in the fifties and sixties. One of his interests was in using microwave energy to assist in freeze-drying, as it provides preferential warming to moist areas of the product without heating areas that are already dry. Copson was the first or only name on all of his patents, but shared one with Dr. Luther Davis Jr, who went on to become head of the Raytheon Research Division in the 1970s and 80s. Copson wrote the book Microwave Heating in 1975, and you can probably still get a used copy on Amazon. A quick Google search suggests that Copson lived from 1919 to 1999. If anyone knows more about him we will gladly post more contributed information!

The History of the Microwave Oven Copyright ©, 1996-2013 by J. Carlton Gallawa Of course, asking "Who Invented the Microwave?" is like asking who invented the electron. Microwave energy is a natural phenomenon that occurs when electric current flows through a conductor. Microwaves are a form of electromagnetic radiation that is very similar to sunlight and radio waves. A Brief History of the Microwave Oven Like many of today's great inventions, the microwave oven was a by-product of another technology. It was during a radar-related research project around 1946 that Dr. Percy Spencer, a self-taught engineer with the Raytheon Corporation, noticed something very unusual. He was testing a new vacuum tube called a magnetron (we are searching for a picture of an actual 1946 magnetron), when he discovered that the candy bar in his pocket had melted. This intrigued Dr. Spencer, so he tried another experiment. This time he placed some popcorn kernels near the tube and, perhaps standing a little farther away, he watched with an inventive sparkle in his eye as the popcorn sputtered, cracked and popped all over his lab.

The next morning, Scientist Spencer decided to put the magnetron tube near an egg. Spencer was joined by a curious colleague, and they both watched as the egg began to tremor and quake. The rapid temperature rise within the egg was causing tremendous internal pressure. Evidently the curious colleague moved in for a closer look just as the egg exploded and splattered hot yolk all over his amazed face. The face of Spencer lit up with a logical scientific conclusion: the melted candy bar, the popcorn, and now the exploding egg, were all attributable to exposure to low-density microwave energy. Thus, if an egg can be cooked that quickly, why not other foods? Experimentation began... Dr. Spencer fashioned a metal box with an opening into which he fed microwave power. The energy entering the box was unable to escape, thereby creating a higher density electromagnetic field. When food was placed in the box and microwave energy fed in, the temperature of the food rose very rapidly. Dr. Spencer had invented what was to revolutionize cooking, and form the basis of a multimillion dollar industry, the microwave oven.

A Bit of Trivia: The "Speedie Weenie" Project In the spring of 1946, Percy Spencer and an associate, P.R. Hanson (Roly Hanson), were working on a secret project they called "the Speedy Weenie". Muriel Withrow remembers the project well. She recalls, "The 'Speedy Weenie' Project was the nickname Mr. Spencer and my boss, Roly Hanson, gave to their secret project, the microwave [oven]" "'Speedie Weenie' meaning 'a quick hot dog!'" (Our thanks to Mrs. Withrow for sharing this little known detail) Nearly 6 Feet Tall, Weighing 750 Pounds Engineers went to work on Spencer's hot new idea, developing and refining it for practical use. By late 1946, the Raytheon Company had filed a patent proposing that microwaves be used to cook food. An oven that heated food using microwave energy was then placed in a Boston restaurant for testing. At last, in 1947, the first commercial microwave oven hit the market.

These primitive units where gigantic and enormously expensive, standing 5 1/2 feet tall, weighing over 750 pounds, and costing about $5000 each. The magnetron tube had to be water-cooled, so plumbing installations were also required. Initial Reactions Were Unfavorable Not surprisingly, many were highly reluctant about these first units, and so they found only limited acceptance. Initial sales were disappointing...but not for long. Further improvements and refinements soon produced a more reliable and lightweight oven that was not only less expensive, but, with the development of a new air-cooled magnetron, there was no longer any need for a plumber. The microwave oven had reached a new level of acceptance, particularly with regard to certain industrial applications. By having a microwave oven available, restaurants and vending companies could now keep products refrigerator-fresh up to the point of service, then heat to order. The result? Fresher food, less waste, and money saved. New and Unusual Applications As the food industry began to recognize the potential and versatility of the microwave oven, its usefulness was put to new tests. Industries began using microwaves to dry potato chips and roast coffee beans and peanuts.

Meats could be defrosted, precooked and tempered. Even the shucking of oysters was made easier by microwaves. Other industries found the diverse applications of microwave heating quite advantageous. In time, microwaves were being used to dry cork, ceramics, paper, leather, tobacco, textiles, pencils, flowers, wet books and match heads. The microwave oven had become a necessity in the commercial market and the possibilities seemed endless. The First "Radarange" In 1947, Raytheon demonstrated the world's first microwave oven and called it a "Radarange," the winning name in an employee contest. Housed in refrigerator-sized cabinets, the first microwave ovens cost between $2,000 and $3,000. Sometime between 1952-55, Tappan introduced the first home model priced at $1295. In 1965 Raytheon acquired Amana Refrigeration. Two years later, the first countertop, domestic oven was introduced. It was a 100-volt microwave oven, which cost just under $500 and was smaller, safer and more reliable than previous models.

By 1975 Sales of Microwave Ovens Exceeded that of Gas Ranges ï¿½Technological advances and further developments led to a microwave oven that was polished and priced for the consumer kitchen. However, there were many myths and fears surrounding these mysterious new electronic "radar ranges." By the seventies, more and more people were finding the benefits of microwave cooking to outweigh the possible risks, and none of them were dying of radiation poisoning, going blind, sterile, or becoming impotent (at least not from using microwave ovens). As fears faded, a swelling wave of acceptance began filtering into the kitchens of America and other countries. Myths were melting away, and doubt was turning into demand. By 1975, sales of microwave ovens would, for the first time, exceed that of gas ranges. The following year, a reported 17% of all homes in Japan were doing their cooking by microwaves, compared with 4% of the homes in the United States the same year. Before long, though, microwave ovens were adorning the kitchens in over nine million homes, or about 14%, of all the homes in the United States.

In 1976, the microwave oven became a more commonly owned kitchen appliance than the dishwasher, reaching nearly 60%, or about 52 million U.S. households. America's cooking habits were being drastically changed by the time and energy-saving convenience of the microwave oven. Once considered a luxury, the microwave oven had developed into a practical necessity for a fast-paced world. An expanding market has produced a style to suit every taste; a size, shape, and color to fit any kitchen, and a price to please almost every pocketbook. Options and features, such as the addition of convection heat, probe and sensor cooking, meet the needs of virtually every cooking, heating or drying application. Today, the magic of microwave cooking has radiated around the globe, becoming an international phenomenon. Inventor Spencer Doctor Spencer continued at Raytheon as a senior consultant until he died at the age of 76. At the time of his death, Dr. Spencer held 150 patents and was considered one of the world's leading experts in the field of microwave energy, despite his lack of a high school education. On September 18, 1999, Dr.

Percy LaBaron Spencer was inducted into the National Inventors Hall of Fame and took his place in history alongside such great inventors as Thomas Edison, the Wright Brothers and George Washington Carver. Click HERE : 1958 Issue of Readers Digest article about Dr. Percy Spencer Click HERE : Wikiverse - A World of Knowledge. Article about Percy Spencer with additional links. More to come on the fascinating history and development of the microwave oven... Note: Photo of Percy Spencer and Patent provided courtesy of The Spencer Family Archives Picture of the earliest microwave oven provided courtesy of The Lemelson-MIT Awards Program's Invention Dimension web site, More about the myths & mysteries of microwave ovens Shop for appliance parts, lawn mower parts and vacuum cleaner parts. Fast, guaranteed delivery. One million parts for 118 brands. Open 7 days a week. Search by part number or model number for best results. If you don't know your model number - try searching by appliance type, brand or part type. Copyright Information Unless otherwise noted, all materials at this cite (including without limitation all text, HTML markup, graphics, and graphic elements) are copyrighted ©, 1989-2013 by J.

Carlton Gallawa. The material available through this site may be freely used for attributed noncommercial educational purposes only. We ask that due credit and notification be given the author. All materials appearing on this website may not be reproduced, stored in any retrieval system, or used in any way for commercial purposes without the express prior written permission of the copyright holder. Send correspondence to: Microtech, P.O. Box 940, Gonzalez, Florida 32560 Disclaimer: The author assumes no liability for any incidental, consequential or other liability from the use of this information. All risks and damages, incidental or otherwise, arising from the use or misuse of the information contained herein are entirely the responsibility of the user. Although careful precaution has been taken in the preparation of this material, we assume no responsibility for omissions or errors. Microwave Oven History • Microwave Facts, Microwave Oven Info • Microwave Master Chef Accidental Discovery Like so many other household gadgets, the original idea for the microwave oven wasn’t borne out a desire to reduce the burden of domestic chores. The history of the microwave began in 1940 when John Randall and Harry Boot invented the cavity magnetron tube at Birmingham University in England.

The magnetron tube quickly became hugely important during World War II as it was used by the Allied forces of Europe and America to emit microwave radar signals to detect distant, Nazi enemy aircraft and ships. In 1945, the American engineer, Percy Spencer was carrying out maintenance work on a live radar set. Whilst working within close proximity to the radar equipment, he felt a tingling sensation throughout his body and noticed that a chocolate bar in his pocket had completely melted. After some investigation he determined that it was the microwaves being emitted by the magnetron tube in the radar set which had caused the chocolate to get warm enough to melt. Percy Spencer experimented further by directing the magnetron tube at kernels of corn. Activating the gun resulted in just what he was hoping – the first microwave popcorn. Percy Spencer then went on to build a metal box with an opening on one side and the magnetron tube poking through into another side of it. He used this box to heat his lunches and a variety of other foods he was curious enough to try out. There’s a story of an occasion where he heated a whole egg in the device which unfortunately resulted in the egg exploding in his colleague’s face.

This incident led to the addition of a door to close the box and prevent any further such incidents. In October 1945 Percy Spencer filed a patent (US 2495429 A) for a “Method of treating foodstuffs” which details the process of heating food using microwaves. In the patent description, Percy Spencer provides examples of where cooking an egg and a potato using his microwave device use a tiny fraction of the energy used with conventional cooking. You can download a scan of the original patent below. Method of Treating Foodstuffs – Patent US2495429A Early Microwave Ovens The first microwave ovens in history were giants compared with the ones we use today. They were first sold in 1947 by Raytheon, an American defence firm. The RadaRange as the machine was known sold for $5000, which would actually be $51,000 US in today’s money. These monsters stood almost 6 feet tall, weighed over a third of a tonne and pumped out a massive 3000 Watts of power.

Of course, these first models were not suitable for domestic use and were sold for use in restaurants, ship’s galleys and large canteens. By 1967, Domestic kitchen counter-top versions of the microwave oven were eventually made available. Sold by the firm Amana, they were priced at US$495 ($3,408 in today’s dollars). Today’s Microwave A company called Litton who were popular in the restaurant business developed the short, wide shape of the microwave oven we are used to seeing today. Sales really took of in USA and Japan from the ten’s of thousands in 1970 to the millions by 1975. By the late 1970’s, technology improvements and cheaper electronic parts meant that microwave ovens became more practical and affordable. In 1986, 1 in 4 US households owned a microwave oven. By 1997, The U.S. Bureau of Labor Statistics reported that a staggering 9 out of 10 American households owned a microwave oven. Today most microwaves continue to follow the same short, wide box format popularised in the 70’s.

You can however buy from a wide range of differing microwave oven types. There are different sizes, colours, capacities and power outputs. Some sit on the kitchen work-top, some are built in to kitchen units and some are hung over the stove. Many microwave ovens today are able to not only microwave food, but can grill, use convection heat and even steam food. Whatever microwave oven you have, don’t just use it for reheating last nights pizza – it can do so much more. So, when you’ve finished eating a delicious plate of microwave slow cooked lamb , thank Percy Spencer and his melted chocolate bar for giving us the idea for the microwave oven all those years ago. Who Invented the Microwave Oven? | Wonderopolis Wonder of the Day #768 Who Invented the Microwave Oven? Who invented the microwave oven? How does a microwave oven work? What was the first microwave oven like? Tags: Listen When your tummy is rumbling, there's one kitchen appliance that can quickly stop the grumbling. From reheating leftover pizza to popping up some light and fluffy popcorn , there's one device that gets the job done in a jiffy. What are we talking about? The microwave oven, of course! You know the drill.

You put your leftovers on a microwave -safe plate, pop it into the microwave , hit a few buttons, and like magic, it's warm and ready to eat. And all this takes place in a few seconds rather than the minutes or hours that the stove and oven can take. Who was the genius who invented this wonderful creation? As a matter of fact, his name was Percy Spencer and his invention was an accident ! Spencer worked for a company named Raytheon, developing microwave radar transmitters during World War II. One day in 1945, he noticed that a candy bar he had in his pocket was starting to melt. The microwaves from the radar set he was working on were cooking the candy bar in his pocket! With a little experimentation, Spencer figured out that the microwaves could be concentrated to heat food . He created the first working microwave oven, and the first food he cooked in it was popcorn. Microwave ovens use microwaves, which are radio waves at a frequency of approximately 2,500 megahertz , to heat food . Microwaves are absorbed by water, fats and sugars and are immediately converted to heat . The microwaves penetrate food quickly, so they cook food evenly and quickly.

Microwaves are not absorbed by most plastics, glass or ceramics , so they are perfect for heating food without heating everything else around the food . This enables microwave ovens to use less energy than other cooking appliances. Raytheon filed a patent for Spencer's microwave cooking process on October 8, 1945. In 1947, Raytheon produced the first commercial microwave oven and called it the “ Radarange ." Would you believe it was almost six feet tall and weighed about 750 pounds? It's true! It was also expensive. The first Radarange was $5,000, which would be equal to over $52,000 today. It would be many years before microwave ovens could be produced and sold inexpensively. Today, millions of kitchens contain a microwave oven. You'll also find them in just about every restaurant kitchen and quite a few convenience stores, too. Whether you're heating up water for coffee, reheating leftovers for lunch or popping a bag of microwave popcorn for a late-night snack, the microwave oven does these things quicker than any other appliance . And that's why it's so popular!

Wonder Contributors Despite its name, no felines were involved in the creation of tomorrow's Wonder of the Day! Try It Out We hope today's Wonder of the Day made you feel all warm inside! Keep the learning going by checking out one or more of the following activities with a friend or family member: How common are microwave ovens today? Find out! Make a list of all the places you can find a microwave oven over the course of the next week. Is there one (or more than one) at school? What about where your parents work? Friends' houses? Convenience stores? Restaurants? Ask a friend to do the same thing and see who can find the most microwave ovens in one week. How much more quickly can a microwave oven cook a product than a conventional oven? Take a trip to the grocery store with an adult. Head to the frozen food aisle and find some example foods that can be cooked in either a microwave or conventional oven. Compare the cooking times for each method. Do the cooking times vary depending upon the type of food? Use a calculator to calculate examples of percentages for how much faster a microwave oven can be. Do you use a microwave oven in your kitchen at home?

Here are some fun, easy recipes you can make with a microwave oven. Choose a recipe or two to try and then check the list of ingredients. You may need to make a trip to the store before you begin. Be sure to get help from a friend or family member! Who Invented the Microwave? Who Invented the Microwave? One of the fastest, most convenient and easiest ways to cook, the microwave or microwave oven is widely used in many households today. Through dielectric heating, this kitchen appliance can efficiently cook or heat various kinds of food. With the aid of radiation, it is possible to heat polarized molecules as well as water. Aside from its important principles and aspects, it is also good to know the history of this cooking equipment including who invented the microwave. The Invention of the Microwave Who invented the microwave? An engineer named Percy Spencer accidentally discovered the use of microwaves to cook food. In happened some time in the 1940s, when he was trying to build radar sets for the commercial electronics manufacturer Raytheon. He noticed that the chocolate bar situated right inside his pocket melted because of the microwaves that were present in the area where he was working.

Thereafter, he went on to experiment and tried to cook popcorn. Next, he and his associates tried to cook an egg, which eventually exploded right in the face of one of them. After that, he and his crew experimented on a metal box, which they fed with microwave power. It became a high-density electromagnetic field, which allowed the food temperature to rise quickly. Raytheon decided to file a patent for Spencer’s invention on October 8, 1945. The kitchen appliance was tested for some time in a restaurant in Boston, Massachusetts. After that, Raytheon decided to build the very first microwave oven called the Radarange. Additional Facts and Other Interesting Information The earlier models of the microwave were big and quite expensive. A basic unit usually measured 1.8 meters or 6 feet tall. Meanwhile, the approximate weight of every product was 340 kilograms or 750 pounds. Furthermore, the price is quite expensive at $5,000 each. In terms of consumption, the earlier form of the microwave consumed approximately three times more electricity compared to present-day models. In 1952, Raytheon decided to license such innovative technology to the company named Tappan Stove.

In 1965, Raytheon decided to acquire Amana, a company that released the countertop Radarange. The cost for the popular home model during that time was $495. In 1986, about 25 percent of U.S. households made use of microwave ovens. In recent years, reports are saying that more or less 90 percent of houses in the United States use microwaves. In terms of design, each microwave oven is comprised of a cooking chamber, a waveguide and a magnetron control circuit. Likewise, it must also have a cavity magnetron as well as a high voltage transformer. The Invention of the Microwave Oven The Invention of the Microwave Oven The microwave oven was a happy accident. Scientists invented the magnetron during World War II. This device emitted microwaves, which the British armed forces used to detect incoming German planes. After the war, scientists continued to improve on the magnetron. In 1946, Percy Spencer, who was working for the Raytheon Corporation, was testing a new version of the magnetron when he noticed that the candy bar in his pocket had melted.

Spencer thought that the magnetron was responsible, and so he placed some unpopped popcorn kernels near the magnetron and flipped the switch. Presto! The popcorn popped. After several more tests, Spencer and his fellow Raytheon scientists were convinced that they had a new invention on their hands. Spencer eventually created a big box that they would place food in for heating. They also discovered that exposure to too much radiation was bad for people. The first microwave ovens looked like a cross between regular oven and a refrigerator. They were 5 feet tall and required a water pipe connection to cool the magnetron after use. Not too many bought those first microwave ovens, but some did. Scientists kept experimenting and refining what they had. Finally, in the 1960s, the small countertop version that we know today was introduced. Graphics courtesy of ClipArt.com

Question: Who invented the Microwave Oven in 1945 in USA?
Answer: Percy LeBaron Spencer